Method for cooking mutton biryani:
How to prepare aknee:Step 1: Lit your gas stove
Step 2: Keep open pressure cooker
Step 3: Put entire oil and heat it
Step 4: Add garam masalas (cinnamon, cloves and cardomoms)
Step 5: After a minute add the entire chopped onion
Step 6: Roast onion till it turns into golden brown (this is important, its okay if onion gets roasted a bit extra, but it not should remain partially roasted)
Step 7: Now add ginger garlic paste and stir well
Step 8: Add salt 1 tsp (or according to taste)
Step 9: Now add the entire mutton
Step 10: Add red chilly powder, coriander powder, and turmeric powder
Step 11: Keep mixing and cooking the mutton for around 15 minutes (or till it starts sticking to cooker, also remember we are NOT adding any water at this point)
Step 12: Now add tomatoes and again cook for some time (some 3 to 4 minutes)
Step 13: Then add green chillies, coriander leaves, and mint leaves and stir well
Step 14: Now add curd, lemon juice and 200ml water and close the lid of cooker and leave it for 10 minutes (or more depending on the hardness of the mutton)

Step 1: After closing the lid of the aknee cooker, soak rice in water and leave it for 10 minutes
Step 2: After 5 minutes of soaking rice in water heat 3 liters of water on another stove (do not use cooker for this, use ordinary aluminum vessel), heat it for 5 minutes
(Note: At this point, your aknee should be ready so put off that stove and rice should ready to be added to this heated water)
Step 3: Remove water from the soaked rice
Step 4: Add rice to the above heated water
Step 5: Add salt 2 tsp (or according to taste)
Step 6: Leave rice to get cooked to some 75% (approximately takes 5 to 7 minutes, the basic idea here is the should be bit raw so that it gets cooked along with aknee as mentioned below)

Now both your aknee and rice are ready, so its time to mix them. Remove water from rice and add rice to the aknee and quickly close the lid of the cooker (ensure that not much of vapor is lost). Leave it for 10 minutes. Now your Muslim mutton biryani is ready to serve. At the time of serving, without disturbing too much keep mixing rice and aknee (do not mix the entire stuff in one shot)).

Enjoy the biryani and do not forget to give feedback in comments. I understand its a challenge to write recipes and make completely unknown people understand them and cook the dish successfully so your comments are vital.